Control system for a fluid drive
A fluid drive assembly has a pump, a variable displacement motor, a fluid
circuit connecting the pump to the motor, and an actuator device for
controlling the displacement of the motor. The actuator device is movable
between a first position at which the displacement of the motor is at a
preselected maximum and a second position at which the displacement of the
motor is at a preselected minimum. A control system for the fluid drive
assembly includes a source of fluid at a first preselected pressure value.
A valve device is connected to the source of fluid and to the actuator
device for controlling the fluid flow therebetween and is movable between
a first position at which the source of fluid is in communication with the
actuator device and a second position at which the source of fluid is
blocked from communication with the actuator device. A first device
automatically moves the valve device to the second position in response to
the fluid pressure in the fluid circuit exceeding a second preselected
pressure level. A second device retains the valve device in the first
position until the fluid pressure in the fluid circuit decreases from the
second preselected pressure level to a third preselected pressure level.
Habiger; Cyril W. (Joliet, IL), Hicks; Leon E. (Joliet, IL) |
Caterpillar Tractor Co.
July 5, 1977|